Motor and fan having motor

Abstract

A fan and a motor thereof are provided. The motor includes a motor drive device. The motor drive device includes a printed circuit board. A control management unit and a voltage converter are arranged on the printed circuit board, the control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed intervals, with each rotation speed interval corresponding to a fixed duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and outputs a pulse width modulation signal having a duty ratio corresponding to the rotation speed interval to which the target rotation speed signal transmitted from the ECU belongs. The voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the pulse width modulation signal having the fixed duty ratio outputted from the control management unit, to control a rotation speed of the motor. The motor drive device performs segment control on the rotation speed of the motor, thereby reducing the cost.

The invention claimed is: 
     
       1. A motor, comprising:
 a stator, 
 a rotor rotatably mounted to the stator, and 
 a motor drive device, wherein 
 the rotor comprises a rotary shaft, an iron core fixed on the rotary shaft and a winding arranged on the iron core, 
 the motor drive device is connected between the winding and a power source, 
 the motor drive device comprises a printed circuit board, 
 a control management unit and a voltage converter are arranged on the printed circuit board, 
 the control management unit is configured to classify target rotation speed signals provided by an ECU into a plurality of rotation speed ranges, each corresponding to a specific output duty ratio, the control management unit is configured to receive a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to the rotation speed range to which the target rotation speed signal transmitted from the ECU falls; and 
 the voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor. 
 
     
     
       2. The motor of  claim 1 , wherein the control management unit is configured to classify the target rotation speed signals provided by the ECU into four rotation speed ranges, which are a stalling range, a low-speed range, a middle-speed range and a full-speed range. 
     
     
       3. The motor of  claim 2 , wherein
 the target rotation speed signal is in the stalling range in a case that a duty ratio of the target rotation speed signal is less than a ratio value X 1 , which is less than 10%, 
 the target rotation speed signal is in the low-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio valve X 1  and less than a ratio value X 2 , which is greater than the ratio valve X 1  and less than or equal to 50%, 
 the target rotation speed signal is in the middle-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio valve X 2  and less than a ratio value X 3 , which is greater than the ratio valve X 2  and less than or equal to 90%, and 
 the target rotation speed signal is in the full-speed range in a case that the duty ratio of the target rotation speed signal is greater than or equal to the ratio value X 3  and less than 100%. 
 
     
     
       4. The motor of  claim 3 , wherein the ratio value X 1  is less than or equal to 5%. 
     
     
       5. The motor of  claim 3 , wherein the ratio value X 2  is less than or equal to 40%. 
     
     
       6. The motor of  claim 3 , wherein the ratio value X 3  is less than or equal to 80%. 
     
     
       7. The motor of  claim 3 , wherein a duty ratio of the voltage regulating signal corresponding to the stalling range is equal to 0, a duty ratio of the voltage regulating signal corresponding to the low-speed range is equal to a ratio value Y 1 , which is greater than or equal to 20% and is less than or equal to 50%, a duty ratio of the voltage regulating signal corresponding to the middle-speed range is equal to a ratio value Y 2 , which is greater than or equal to 50% and less than or equal to 80%, and a duty ratio of the voltage regulating signal corresponding to the full-speed range is equal to 100%. 
     
     
       8. The motor of  claim 1 , wherein the control management unit is configured to classify the target rotation speed signals provided by the ECU into three rotation speed ranges, which are a stalling range, a low-speed range and a full-speed range, and a duty ratio of the voltage regulating signal corresponding to the low-speed range ranges from 20% to 80%. 
     
     
       9. The motor of  claim 1 , wherein the control management unit comprises:
 a command manager configured to determine the rotation speed range to which the target rotation speed signal transmitted from the ECU falls, and output a target voltage in an analog form based on the duty ratio corresponding to the rotation speed range; and 
 a PWM generator, in which a triangular wave oscillator for generating a triangular wave is arranged, wherein the target voltage is compared with the triangular wave to output the pulse width modulation signal. 
 
     
     
       10. The motor of  claim 1 , wherein the voltage converter comprises a diode and an MOS transistor connected between a positive electrode of the power source and ground in series, a cathode of the diode is connected to the positive electrode of the power source, an anode of the diode is connected to a drain of the MOS transistor, and a source of the MOS transistor is grounded, a gate of the MOS transistor receives the voltage regulating signal outputted from the control management unit, and the anode and the cathode of the diode are configured to be connected to the motor. 
     
     
       11. The motor of  claim 1 , wherein
 the stator comprises a cylindrical case, a plurality of permanent magnets arranged at an inner wall of the cylindrical case, and an endcap, 
 an opening is formed at one end of the cylindrical case in an axial direction, and the endcap is fixed at the opening of the cylindrical case in the axial direction, 
 the motor further comprises a brush assembly arranged on the endcap, the brush assembly comprises a brush holder and two brushes arranged on the brush holder, 
 a commutator electrically connected with the winding is arranged on the rotor, the brush is in sliding contact with the commutator, and 
 the printed circuit board of the motor drive device is arranged on the brush holder. 
 
     
     
       12. The motor of  claim 11 , wherein
 the brush holder is in an annular shape with a through hole at the center, 
 the commutator on the rotor passes through the through hole at the center of the brush holder, 
 the two brushes are arranged on the brush holder at an interval in a circumferential direction, and 
 a mounting groove is arranged on the brush holder, and the printed circuit board of the motor drive device is accommodated in the mounting groove. 
 
     
     
       13. The motor of  claim 12 , wherein an arc-shaped hole for dissipating heat is arranged on a bottom wall of the mounting groove, and a heat dissipation hole in communication with the arc-shaped hole is arranged at a position of the endcap corresponding to the arc-shaped hole. 
     
     
       14. The motor of  claim 13 , wherein the motor drive device further comprises a filtering unit connected with the voltage converter arranged on the printed circuit board, the filtering unit comprises an inductor, a first capacitor and a second capacitor, the inductor is connected between the power source and the voltage converter, one end of the inductor connected with the power source is grounded via the first capacitor, one end of the inductor connected to the voltage converter is grounded via the second capacitor, and the inductor, the first capacitor and the second capacitor are located at a position of the printed circuit board directly facing the arc-shaped hole. 
     
     
       15. The motor of  claim 14 , wherein the motor further comprises a radiator, and the radiator is mounted outside the endcap of the motor and is attached to an outer surface of the endcap of the motor closely. 
     
     
       16. The motor of  claim 15 , wherein the radiator comprises a substrate in an annular-sector shape and a side wall perpendicularly extending from an outer edge of the substrate, a projection portion is arranged at a position of the substrate corresponding to the heat dissipation hole and the arc-shaped hole, the projection portion extends into the heat dissipation hole and the arc-shaped hole, to be close to the printed circuit board. 
     
     
       17. The motor of  claim 11 , wherein
 a connector, for connecting the motor drive device with the power source and the ECU, is integrated at one end of the brush holder, 
 the connector comprises a base and a shielding housing covered on the base, 
 three slots are formed on the base, one end of each of three input terminals is accommodated in one of the slot of the base, and is connected with a wire, and the wire extends out of one end of the base, 
 the other end of each of the three input terminals extends out of the other end of the base, and is fixed on the printed circuit board. 
 
     
     
       18. The motor of  claim 17 , wherein two output terminals are arranged on the printed circuit board, and the voltage converter is configured to output a voltage to the winding by the two output terminals. 
     
     
       19. The motor of  claim 1 , wherein
 the stator comprises a cylindrical case, an opening is formed at one end of the cylindrical case in an axial direction, and an endcap is fixed at the opening of the cylindrical case in the axial direction, 
 a brush holder is arranged in a first accommodating space of the endcap, and 
 the printed circuit board of the motor drive device is arranged in a second accommodating space of the endcap. 
 
     
     
       20. The motor of  claim 19 , wherein the first accommodating space is located at an inner side of the endcap, and the second accommodating space is located at an outer side of the endcap. 
     
     
       21. The motor of  claim 19 , wherein
 the motor drive device comprises a connector, 
 the connector is arranged at a coupling position where the endcap is coupled to the case, and comprises a holding portion held at the coupling position where the endcap is coupled to the case and a mounting portion extending from one end of the holding portion, and 
 three input terminals for connecting the power source and the ECU, and two output terminals for outputting a voltage to the winding are arranged on the mounting portion. 
 
     
     
       22. The motor of  claim 21 , wherein one end of each of the input terminals is connected with a wire, and the other end of each of the input terminals extends outside the mounting portion towards the endcap. 
     
     
       23. The motor of  claim 22 , wherein
 two terminal grooves are arranged on the mounting portion, 
 each of the output terminals is in a U shape, and comprises two vertical arms and a horizontal portion, 
 the horizontal portion is arranged in the mounting portion, and 
 one vertical arm of the output terminal extends outside the mounting portion towards the endcap, and two side walls of the other vertical arm of the output terminal bends oppositely to form a ring-shaped portion and are inserted into the terminal groove corresponding to the ring-shaped portion. 
 
     
     
       24. The motor of  claim 23 , wherein
 a brush and a metal sheet are arranged on the brush holder, 
 the metal sheet is configured to connect the brush to the output terminal, and 
 the metal sheet is inserted into the terminal groove, and is electrically connected to the other vertical arm of the output terminal. 
 
     
     
       25. The motor of  claim 24 , wherein a recess portion is recessed at an outer side of the endcap, to accommodate the printed circuit board of the motor drive device. 
     
     
       26. The motor of  claim 25 , wherein
 a through slot is arranged on a bottom wall of the recess portion, and 
 the other end of the input terminal of the connector and one vertical arm of the output terminal pass through the through slot to be inserted onto the printed circuit board. 
 
     
     
       27. The motor of  claim 24 , wherein the motor further comprises a sealing cover for fixing the printed circuit board onto the endcap. 
     
     
       28. A fan, comprising:
 the motor according to  claim 1 , and 
 an impeller driven by the motor.